Metal casting typically involves die casting. Molten metal is poured to fill the interior cavity of a die. The shape of the metal is controlled by the design of the die. In virtually all cases, the shape of the product is well defined (e.g., casting of machine parts). That is to say, if casting is complete and has been carried out as intended, the resultant workpiece will be the same every time.
Die casting is also frequently employed where an artistic shape is to be cast (busts of famous people, objects of nature, etc.). Where an artistic piece is to be mass produced, it is also essential that the casting process faithfully reproduces the object. In sum, the fact that it is purchased for artistic appeal does not change the fact that the resultant workpiece needs to be manufactured identically each time.